Custom Item integration with Piglins (#6914)

patches/minecraft/net/minecraft/entity/monster/piglin/PiglinEntity.java.patch

@@ -0,0 +1,11 @@
+--- a/net/minecraft/entity/monster/piglin/PiglinEntity.java
++++ b/net/minecraft/entity/monster/piglin/PiglinEntity.java
+@@ -367,7 +367,7 @@
+    }
+ 
+    protected void func_234439_n_(ItemStack p_234439_1_) {
+-      if (p_234439_1_.func_77973_b() == PiglinTasks.field_234444_a_) {
++      if (p_234439_1_.isPiglinCurrency()) {
+          this.func_184201_a(EquipmentSlotType.OFFHAND, p_234439_1_);
+          this.func_233663_d_(EquipmentSlotType.OFFHAND);
+       } else {

patches/minecraft/net/minecraft/entity/monster/piglin/PiglinTasks.java.patch

@@ -0,0 +1,38 @@
+--- a/net/minecraft/entity/monster/piglin/PiglinTasks.java
++++ b/net/minecraft/entity/monster/piglin/PiglinTasks.java
+@@ -231,7 +231,7 @@
+       ItemStack itemstack = p_234477_0_.func_184586_b(Hand.OFF_HAND);
+       p_234477_0_.func_184611_a(Hand.OFF_HAND, ItemStack.field_190927_a);
+       if (p_234477_0_.func_234421_eJ_()) {
+-         boolean flag = func_234492_b_(itemstack.func_77973_b());
++         boolean flag = itemstack.isPiglinCurrency();
+          if (p_234477_1_ && flag) {
+             func_234475_a_(p_234477_0_, func_234524_k_(p_234477_0_));
+          } else if (!flag) {
+@@ -317,7 +317,7 @@
+          return false;
+       } else if (func_234453_C_(p_234474_0_) && p_234474_0_.func_213375_cj().func_218191_a(MemoryModuleType.field_234103_o_)) {
+          return false;
+-      } else if (func_234492_b_(item)) {
++      } else if (p_234474_1_.isPiglinCurrency()) {
+          return func_234455_E_(p_234474_0_);
+       } else {
+          boolean flag = p_234474_0_.func_234437_l_(p_234474_1_);
+@@ -417,7 +417,7 @@
+    }
+ 
+    protected static boolean func_234489_b_(PiglinEntity p_234489_0_, ItemStack p_234489_1_) {
+-      return !func_234453_C_(p_234489_0_) && !func_234451_A_(p_234489_0_) && p_234489_0_.func_234421_eJ_() && func_234492_b_(p_234489_1_.func_77973_b());
++      return !func_234453_C_(p_234489_0_) && !func_234451_A_(p_234489_0_) && p_234489_0_.func_234421_eJ_() && p_234489_1_.isPiglinCurrency();
+    }
+ 
+    protected static void func_234468_a_(PiglinEntity p_234468_0_, LivingEntity p_234468_1_) {
+@@ -518,7 +518,7 @@
+    public static boolean func_234460_a_(LivingEntity p_234460_0_) {
+       for(ItemStack itemstack : p_234460_0_.func_184193_aE()) {
+          Item item = itemstack.func_77973_b();
+-         if (item instanceof ArmorItem && ((ArmorItem)item).func_200880_d() == ArmorMaterial.GOLD) {
++         if (itemstack.makesPiglinsNeutral(p_234460_0_)) {
+             return true;
+          }
+       }

src/main/java/net/minecraftforge/common/extensions/IForgeItem.java

@@ -36,7 +36,10 @@ import net.minecraft.entity.LivingEntity;
 import net.minecraft.entity.ai.attributes.Attribute;
 import net.minecraft.entity.ai.attributes.AttributeModifier;
 import net.minecraft.entity.item.ItemEntity;
+import net.minecraft.entity.monster.piglin.PiglinTasks;
 import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.item.ArmorItem;
+import net.minecraft.item.ArmorMaterial;
 import net.minecraft.item.Items;
 import net.minecraft.inventory.EquipmentSlotType;
 import net.minecraft.item.Item;
@@ -113,6 +116,29 @@ public interface IForgeItem
         return ActionResultType.PASS;
     }
 
+    /**
+     * Called by Piglins when checking to see if they will give an item or something in exchange for this item.
+     *
+     * @return True if this item can be used as "currency" by piglins
+     */
+    default boolean isPiglinCurrency(ItemStack stack)
+    {
+        return stack.getItem() == PiglinTasks.field_234444_a_;
+    }
+
+    /**
+     * Called by Piglins to check if a given item prevents hostility on sight. If this is true the Piglins will be neutral to the entity wearing this item, and will not
+     * attack on sight. Note: This does not prevent Piglins from becoming hostile due to other actions, nor does it make Piglins that are already hostile stop being so.
+     *
+     * @param wearer The entity wearing this ItemStack
+     *
+     * @return True if piglins are neutral to players wearing this item in an armor slot
+     */
+    default boolean makesPiglinsNeutral(ItemStack stack, LivingEntity wearer)
+    {
+        return stack.getItem() instanceof ArmorItem && ((ArmorItem) stack.getItem()).getArmorMaterial() == ArmorMaterial.GOLD;
+    }
+
     /**
      * Called by CraftingManager to determine if an item is reparable.
      *

src/main/java/net/minecraftforge/common/extensions/IForgeItemStack.java

@@ -450,4 +450,27 @@ public interface IForgeItemStack extends ICapabilitySerializable<CompoundNBT>
     {
         return getStack().getItem().isRepairable(getStack());
     }
+
+    /**
+     * Called by Piglins when checking to see if they will give an item or something in exchange for this item.
+     *
+     * @return True if this item can be used as "currency" by piglins
+     */
+    default boolean isPiglinCurrency()
+    {
+        return getStack().getItem().isPiglinCurrency(getStack());
+    }
+
+    /**
+     * Called by Piglins to check if a given item prevents hostility on sight. If this is true the Piglins will be neutral to the entity wearing this item, and will not
+     * attack on sight. Note: This does not prevent Piglins from becoming hostile due to other actions, nor does it make Piglins that are already hostile stop being so.
+     *
+     * @param wearer The entity wearing this ItemStack
+     *
+     * @return True if piglins are neutral to players wearing this item in an armor slot
+     */
+    default boolean makesPiglinsNeutral(LivingEntity wearer)
+    {
+        return getStack().getItem().makesPiglinsNeutral(getStack(), wearer);
+    }
 }